SnRK1 stimulates the histone H3K27me3 demethylase JMJ705 to regulate a transcriptional switch to control energy homeostasis

2021 ◽  
Author(s):  
Wentao Wang ◽  
Yue Lu ◽  
Junjie Li ◽  
Xinran Zhang ◽  
Fangfang Hu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Energy Homeostasis ◽  
Low Energy ◽  
Transcriptional Networks ◽  
Energy Status ◽  
Α Subunit ◽  
Cellular Energy ◽  
Energy Stress ◽  
Demethylase Activity ◽  
Regulated Gene Expression

Abstract Plant SNF1-Related Kinase1 (SnRK1) is an evolutionarily conserved energy-sensing protein kinase that orchestrates transcriptional networks to maintain cellular energy homeostasis when energy supplies become limited. However, the mechanism by which SnRK1 regulates this gene expression switch to gauge cellular energy status remains largely unclear. In this work, we show that the rice histone H3K27me3 demethylase JMJ705 is required for low energy stress tolerance in rice plants. The genetic inactivation of JMJ705 resulted in similar effects as those of the rice snrk1 mutant on the transcriptome, which impairs not only the promotion of the low energy stress-triggered transcriptional program but also the repression of the program under an energy-sufficient state. We show that the α-subunit of OsSnRK1 interacts with and phosphorylates JMJ705 to stimulate its H3K27me3 demethylase activity. Further analysis revealed that JMJ705 directly targets a set of low energy stress-responsive transcription factor genes. These results uncover the chromatin mechanism of SnRK1-regulated gene expression in both energy-sufficient and -limited states in plants and suggest that JMJ705 functions as an upstream regulator of the SnRK1α-controlled transcriptional network.

Molecular Regulation of Energy Balance

2019 ◽  
Author(s):  
D. Grahame Hardie ◽  
A. Mark Evans
Keyword(s):  
Energy Balance ◽  
Energy Homeostasis ◽  
Adenine Nucleotides ◽  
Kinase Domain ◽  
Cellular Level ◽  
Whole Body ◽  
Energy Status ◽  
Α Subunit ◽  
Cellular Energy ◽  
Synthetic Drugs

AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that monitors the levels of AMP and ADP relative to ATP. If increases in AMP:ATP and/or ADP:ATP ratios are detected (indicating a reduction in cellular energy status), AMPK is activated by the canonical mechanism involving both allosteric activation and enhanced net phosphorylation at Thr172 on the catalytic subunit. Once activated, AMPK phosphorylates dozens of downstream targets, thus switching on catabolic pathways that generate ATP and switching off anabolic pathways and other energy-consuming processes. AMPK can also be activated by non-canonical mechanisms, triggered either by glucose starvation by a mechanism independent of changes in adenine nucleotides, or by increases in intracellular Ca2+ in response to hormones, mediated by the alternate upstream kinase CaMKK2. AMPK is expressed in almost all eukaryotic cells, including neurons, as heterotrimeric complexes comprising a catalytic α subunit and regulatory β and γ subunits. The α subunits contain the kinase domain and regulatory regions that interact with the other two subunits. The β subunits contain a domain that, with the small lobe of the kinase domain on the α subunit, forms the “ADaM” site that binds synthetic drugs that are potent allosteric activators of AMPK, while the γ subunits contain the binding sites for the classical regulatory nucleotides, AMP, ADP, and ATP. Although much undoubtedly remains to be discovered about the roles of AMPK in the nervous system, emerging evidence has confirmed the proposal that, in addition to its universal functions in regulating energy balance at the cellular level, AMPK also has cell- and circuit-specific roles at the whole-body level, particularly in energy homeostasis. These roles are mediated by phosphorylation of neural-specific targets such as ion channels, distinct from the targets by which AMPK regulates general, cell-autonomous energy balance. Examples of these cell- and circuit-specific functions discussed in this review include roles in the hypothalamus in balancing energy intake (feeding) and energy expenditure (thermogenesis), and its role in the brainstem, where it supports the hypoxic ventilatory response (breathing), increasing the supply of oxygen to the tissues during systemic hypoxia.

Cellular energy status modulates translational control mechanisms in ischemic-reperfused rat hearts

2005 ◽  
Vol 289 (3) ◽  
pp. H1242-H1250 ◽  
Author(s):  
Stephen J. Crozier ◽  
Thomas C. Vary ◽  
Scot R. Kimball ◽  
Leonard S. Jefferson
Keyword(s):  
Translational Control ◽  
Mrna Translation ◽  
Initiation Factor ◽  
Control Mechanisms ◽  
Energy Status ◽  
Α Subunit ◽  
Energy Substrate ◽  
Cellular Energy ◽  
Rat Hearts ◽  
Induced Changes

Mechanisms regulating ischemia and reperfusion (I/R)-induced changes in mRNA translation in the heart are poorly defined, as are the factors that initiate these changes. Because cellular energy status affects mRNA translation under physiological conditions, it is plausible that I/R-induced changes in translation may in part be a result of altered cellular energy status. Therefore, the purpose of the studies described herein was to compare the effects of I/R with those of altered energy substrate availability on biomarkers of mRNA translation in the heart. Isolated adult rat hearts were perfused with glucose or a combination of glucose plus palmitate, and effects of I/R on various biomarkers of translation were subsequently analyzed. When compared with hearts perfused with glucose plus palmitate, hearts perfused with glucose alone exhibited increased phosphorylation of eukaryotic elongation factor (eEF)2, the α-subunit of eukaryotic initiation factor (eIF)2, and AMP-activated protein kinase (AMPK), and these hearts also exhibited enhanced association of eIF4E with eIF4E binding protein (4E-BP)1. Regardless of the energy substrate composition of the buffer, phosphorylation of eEF2 and AMPK was greater than control values after ischemia. Phosphorylation of eIF2α and eIF4E and the association of eIF4E with 4E-BP1 were also greater than control values after ischemia but only in hearts perfused with glucose plus palmitate. Reperfusion reversed the ischemia-induced increase in eEF2 phosphorylation in hearts perfused with glucose and reversed ischemia-induced changes in eIF4E, eEF2, and AMPK phosphorylation in hearts perfused with glucose plus palmitate. Because many ischemia-induced changes in mRNA translation are mimicked by the removal of a metabolic substrate under normal perfusion conditions, the results suggest that cellular energy status represents an important modulator of I/R-induced changes in mRNA translation.

AMP kinase (PRKAA1)

2014 ◽  
Vol 67 (9) ◽  
pp. 758-763 ◽  
Author(s):  
Sukriti Krishan ◽  
Des R Richardson ◽  
Sumit Sahni
Keyword(s):  
Energy Homeostasis ◽  
Atp Synthesis ◽  
Cellular Growth ◽  
Α Subunit ◽  
Cellular Energy ◽  
Therapeutic Drugs ◽  
Energy Sensor ◽  
Energy Consuming ◽  
Cardiac Disorders ◽  
Amp Activated Protein Kinase

The PRKAA1 gene encodes the catalytic α-subunit of 5′ AMP-activated protein kinase (AMPK). AMPK is a cellular energy sensor that maintains energy homeostasis within the cell and is activated when the AMP/ATP ratio increases. When activated, AMPK increases catabolic processes that increase ATP synthesis and inhibit anabolic processes that require ATP. Additionally, AMPK also plays a role in activating autophagy and inhibiting energy consuming processes, such as cellular growth and proliferation. Due to its role in energy metabolism, it could act as a potential target of many therapeutic drugs that could be useful in the treatment of several diseases, for example, diabetes. Moreover, AMPK has been shown to be involved in inhibiting tumour growth and metastasis, and has also been implicated in the pathology of neurodegenerative and cardiac disorders. Hence, a better understanding of AMPK and its role in various pathological conditions could enable the development of strategies to use it as a therapeutic target.

scholarly journals OR09-04 Common Genetic Variants Associated with SERPINA6 Expression in Liver Influence Cortisol-Responsive Transcriptional Networks in Human Adipose Tissue

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Sean A Bankier ◽  
Andrew A Crawford ◽  
Lingfei Wang ◽  
Katyayani Sukhavasi ◽  
Raili Ermel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Coronary Artery ◽  
Genetic Variants ◽  
Plasma Cortisol ◽  
Transcriptional Networks ◽  
Genome Wide ◽  
Common Genetic Variants ◽  
Regulated Gene Expression ◽  
Genome Wide Significance

Abstract A genome wide meta-analysis by the CORtisol NETwork (CORNET) consortium(1) has identified genetic variants spanning the SERPINA6/SERPINA1 locus on chromosome 14, associated with morning plasma cortisol and predictive of cardiovascular disease (Crawford et al, Unpublished). SERPINA6 encodes Corticosteroid Binding Globulin (CBG), responsible for binding most cortisol in blood and putatively mediating delivery of cortisol to target tissues. We hypothesised that genetic variants in SERPINA6 influence CBG expression in liver and cortisol delivery to extra-hepatic tissues, influencing cortisol-regulated gene expression. The Stockholm Tartu Atherosclerosis Reverse Networks Engineering Task study (STARNET)(2) provides RNA sequencing data in 9 vascular and metabolic tissues from 600 genotyped individuals (mean age 65.8, 70.3% male) undergoing coronary artery bypass grafting. We used STARNET to identify SNPs associated with plasma cortisol at genome wide significance in CORNET as cis-eQTLs for SERPINA6 in liver and as trans-eQTLs for the expression of genes across STARNET tissues. Causal inference methodologies(3) were then employed for the network reconstruction of these trans-genes and their downstream targets. We identified 21 SNPs that both were associated with cortisol at genome wide significance in CORNET (p ≤ 5x10-8) and were cis-eQTLs for SERPINA6 expression in liver (q ≤ 0.05). Moreover, these SNPs were trans-eQTLs for sets of genes in liver, subcutaneous and visceral abdominal adipose tissue, with over-representation of known glucocorticoid-regulated genes in adipose. The highest confidence gene network identified was specific to subcutaneous adipose, with the interferon regulatory trans-gene, IRF2, controlling a putative glucocorticoid-regulated network. Targets in this network include LDB2 and LIPA, both associated with coronary artery disease. We conclude that variants in the SERPINA6/SERPINA1 locus mediate their effect on plasma cortisol through variation in SERPINA6 expression in liver, and in turn affect gene expression in extra-hepatic tissues through modulating cortisol delivery. This supports a dynamic role for CBG in modulating cortisol delivery to tissues. The cortisol-responsive gene networks identified here represent candidate pathways to mediate cardiovascular risk attributable to elevated cortisol. (1) Bolton, et al. (2014) PLOS Genet. 10:e1004474., (2) Franzén et al. (2016). Science 353:827., (3) Wang and Michoel. (2017). PLOS Comput. Biol. 13:e1005703.

scholarly journals Sirtuin 1 and Sirtuin 3: Physiological Modulators of Metabolism

2012 ◽  
Vol 92 (3) ◽  
pp. 1479-1514 ◽  
Author(s):  
Ruben Nogueiras ◽  
Kirk M. Habegger ◽  
Nilika Chaudhary ◽  
Brian Finan ◽  
Alexander S. Banks ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Sirtuin 1 ◽  
Energy Status ◽  
Metabolic Processes ◽  
Sirtuin 3 ◽  
Nonalcoholic Fatty Liver ◽  
Cellular Energy ◽  
Diet Induced Obesity ◽  
Energy Stores

The sirtuins are a family of highly conserved NAD+-dependent deacetylases that act as cellular sensors to detect energy availability and modulate metabolic processes. Two sirtuins that are central to the control of metabolic processes are mammalian sirtuin 1 (SIRT1) and sirtuin 3 (SIRT3), which are localized to the nucleus and mitochondria, respectively. Both are activated by high NAD+ levels, a condition caused by low cellular energy status. By deacetylating a variety of proteins that induce catabolic processes while inhibiting anabolic processes, SIRT1 and SIRT3 coordinately increase cellular energy stores and ultimately maintain cellular energy homeostasis. Defects in the pathways controlled by SIRT1 and SIRT3 are known to result in various metabolic disorders. Consequently, activation of sirtuins by genetic or pharmacological means can elicit multiple metabolic benefits that protect mice from diet-induced obesity, type 2 diabetes, and nonalcoholic fatty liver disease.

scholarly journals An inhibited conformation for the protein kinase domain of theSaccharomyces cerevisiaeAMPK homolog Snf1

2010 ◽  
Vol 66 (9) ◽  
pp. 999-1002 ◽  
Author(s):  
Michael J. Rudolph ◽  
Gabriele A. Amodeo ◽  
Liang Tong
Keyword(s):  
Protein Kinase ◽  
Active Site ◽  
Energy Homeostasis ◽  
Kinase Domain ◽  
Α Subunit ◽  
Protein Kinase Domain ◽  
Cellular Energy ◽  
Glucose Depletion ◽  
Inhibitory Domain ◽  
Amp Activated Protein Kinase

AMP-activated protein kinase (AMPK) is a master metabolic regulator for controlling cellular energy homeostasis. Its homolog in yeast, SNF1, is activated in response to glucose depletion and other stresses. The catalytic (α) subunit of AMPK/SNF1 in yeast (Snf1) contains a protein Ser/Thr kinase domain (KD), an auto-inhibitory domain (AID) and a region that mediates interactions with the two regulatory (β and γ) subunits. Here, the crystal structure of residues 41–440 of Snf1, which include the KD and AID, is reported at 2.4 Å resolution. The AID is completely disordered in the crystal. A new inhibited conformation of the KD is observed in a DFG-out conformation and with the glycine-rich loop adopting a structure that blocks ATP binding to the active site.

scholarly journals Hypothalamic NAD+-Sirtuin Axis: Function and Regulation

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 396
Author(s):  
Eun Roh ◽  
Min-Seon Kim
Keyword(s):  
Energy Homeostasis ◽  
Therapeutic Potential ◽  
Energy Status ◽  
Transcriptional Responses ◽  
Cellular Energy ◽  
Global Health Care ◽  
Neuronal Functions ◽  
Care Problems ◽  
Circadian Physiology ◽  
Metabolic Regulators

The rapidly expanding elderly population and obesity endemic have become part of continuing global health care problems. The hypothalamus is a critical center for the homeostatic regulation of energy and glucose metabolism, circadian rhythm, and aging-related physiology. Nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase sirtuins are referred to as master metabolic regulators that link the cellular energy status to adaptive transcriptional responses. Mounting evidence now indicates that hypothalamic sirtuins are essential for adequate hypothalamic neuronal functions. Owing to the NAD+-dependence of sirtuin activity, adequate hypothalamic NAD+ contents are pivotal for maintaining energy homeostasis and circadian physiology. Here, we comprehensively review the regulatory roles of the hypothalamic neuronal NAD+-sirtuin axis in a normal physiological context and their changes in obesity and the aging process. We also discuss the therapeutic potential of NAD+ biology-targeting drugs in aging/obesity-related metabolic and circadian disorders.

scholarly journals The Landscape of Subcellular Long Non-coding RNAs Links Organelle Metabolic Homeostasis

2020 ◽  
Author(s):  
Ling-jie Sang ◽  
Huai-Qiang Ju ◽  
Zuo-zhen Yang ◽  
Qi-wei Ge ◽  
Zhen Zhang ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Tca Cycle ◽  
Functional Annotations ◽  
Cellular Energy ◽  
Cellular Processes ◽  
Energy Stress ◽  
The Tca Cycle ◽  
Non Coding Rnas ◽  
Complex Architecture ◽  
New Strategies

Abstract Organelles entail specialized molecules to regulate their essential cellular processes. However, systematically elucidating the subcellular distribution of functional molecules such as long non-coding RNAs (lncRNAs) in tissue homeostasis and diseases has not been fully achieved. Here, we characterized the organelle-associated lncRNAs from mitochondria, lysosome, and endoplasmic reticulum (ER), respectively, and revealed the diverse and abundant distribution of lncRNAs. Among them, we identified mitochondrial lncRNA Growth-Arrest-Specific 5 (GAS5) as a tumor suppressor in maintaining cellular energy homeostasis. Mechanistically, energy stress-induced GAS5 modulated mitochondria TCA flux by declining metabolic tandem association of FH-MDH2-CS, the canonical members of the TCA cycle. Remarkably, the expression of GAS5 negatively related with levels of its associated mitochondrial metabolic enzymes and breast cancer development. Together with the detailed functional annotations, this subcellular lncRNA identification revealed the human cell’s inquisitively complex architecture, aiding in the development of new strategies for the clinical application of organelle-associated lncRNAs.

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